In article , Andy Wade
writes
fred wrote:

and a 1971 patent.

Yes I noticed that and tried to search for the details of the patent but
I got bogged down in rubbish sites, did you find a detailed listing?

Try
http://v3.espacenet.com/publicationD...9710616&NR=123
5849A&DB=EPODOC&locale=en_GB&CC=GB&FT=D

Thanks, a bit dry sic but worth a read, emphasis appears to be on flow
regulation and anti-scald rather than the uniqueness of the uninsulated
element but the need for long insulating flow tubes is mentioned.

Application first filed 1967.
--
fred
BBC3, ITV2/3/4, channels going to the DOGs